Apparatus for tank gauging



Oct. 31, 1939. F. M. HESS APPARATUS FOR TANK GAUGING Filed March 31, 1938 Zia 0Z1 5s: 7'? 1157/]. 55/655 Patented Oct. 31, 1939 UNITED STATES PATENT OFFICE Application March 31,

Claims.

My invention relates to an apparatus for ganging the liquid content of tanks of any shape, which is particularly applicable to tanks of varying volume per unit depth, such as horizontally '5 disposed tanks of cylindrical or elliptical crosssection.

In my co-pending patent application Serial No. 154,349 an accurate method and means is described for gauging all classes of tanks; the present application relating to an improvement on the former, primarily in the apparatus employed for translating vertical rise or fall of a tank float into indications and/or recordings proportional to volumetric change. Such apparatus involves means for transposing such rise or fall into rotary motion proportionated to the varying liquid areas per unit depth and is eflected through a novel combination of a winding drum (actuated by the tank float) rotatably mounted in a rack which is caused to oscillate through a predetermined angle by a cam train itself driven by said drum. The angle involved and the cam contour may be readily geometrically developed from the tank crosssection, insuring the highest accuracy in gauging, 5 while the absence of fine pitch driving screws makes for a supersensitivity carried to the optimum by the inclusion of a floating spring in the Winding drum. The indicating and/or recording portion of the apparatus, as in my co-pending application, may be calibrated to read in any desired volumetric units.

In order that the invention may be better understood, reference is made to the accompanying drawing where like parts are numbered the same throughout. Fig. 1 represents a side elevation of an assembled embodiment of my invention, Fig. 2 is a sectional view taken on the line 22 of Fig. 1, while Fig. 3 is. a fragmentary view of one of the partition walls showing the extent of movement of the previously mentioned oscillating rack. Fig. 4 is an enlarged detail of the knuckle carrying the float cord, while Fig. 5 is a side elevation of the float and float casing drawn at a greatly reduced scale to that of Fig. 1.

Referring to Fig. 1: I, 2 and 3 represent partition walls, conveniently circular in shape, held in rigid spaced relationship by the tubular members 4, 5, 6 and 1 and bolts 8, 9, l0 and H with their respective nuts |2, l3, l4 and I5. Between walls I and 2, is disposed the rack I6, oscillatively supported by the shafts I1 and I6, the latter being rigidly attached to the wall I while the shaft is rotatably mounted in bearings drilled in the Walls 2 and 3. The rack I6 is constructed of two 55 parallel rectangular plates l9 and 20, held in rigid 1938, Serial No. 199,218

spaced relationship by the plate 2| and rod 22, and appears in its vertical (neutral) position in dotted outline in Fig. 2.

In the upper portion of the rack i6 is disposed the shaft 23, journalled in bearings 24 and 25, and carrying the rigidly mounted gear 26. The latter engages the gear 21 fixed on the shaft 28 hung in bearings 29 and 36; these and the preceding bearings being suitably reduced in diameter to prevent lateral movement of the respective shafts. On the shaft 28 is also mounted the winding drum 3| helically grooved (32) around its entire periphery for receiving the cord 6|]; the diameter and/or length of the drum being predetermined for the particular tank involved. The bracket 33, rigidly fastened to the lower portion of the frame l6, terminates in the axially drilled (61) stirrup 34 fitted with the throat pin 35 on which is rotatably mounted the grooved roller 38 and the knuckle 36, the latter having a tubular extension 31; the immediately above described parts appearing in detail in Fig. 4.

Referring again to- Fig. 1: the tube 31 (carrying the float cord 60) is provided with the fixed clamp or lug 39 which is movably linked by the lever 40 through pins and 46 to the sleeve 4|. The latter, carrying the key 42, is slidably mount ed on the bearing 43 which in turn is rigid on the shaft H and spirally grooved (44) for engagement with the aforesaid key. The rotation of shaft l7, according to direction, causes the sleeve 4| and its linked tube 31 to advance or recede; indicated in their extreme right hand positions by 4| and 3'! respectively.

On the extension of shaft 23 beyond the wall 2 is rigidly mounted the gear 41 enmeshing with the gear 56 which is fixed on shaft I! as is also the internally grooved cam 5|. On the pivot 52, which is rigidly attached to the wall 2, is oscillatively mounted the cam lever 49, the lower end thereof carrying the roller 53 which engages the cam groove; the upper end being slotted and en-- gaging the roller 54 mounted on a further extension of shaft 23. The contour of the cam groove is such that the lever 49 will oscillate shaft 23 between the radial lines 55 and 56 (Fig. 2 and Fig. 3) the slot 51 in wall 2, through which shaft 23 projects, being of sufficient length to permit of such oscillation between points 58 and 59 as shown in Fi 3.

' The float cord 60 is attached to drum 3| at 6|, and then passing downwardly through tube 31 and over roller 38, emerges through slot 62 in plate 2| for attachment to float 63; the slot 62 being of sufficient length to avoid impingement of the float cord during the movement of rack [6 between the radial lines 55 and 5E. The float 63 (Fig. 5) is shown as suspended in the slotted, sectional casing fi l, the sliding section 55 permitting the casing to be telescoped sufficiently for introduction to a tank and thence extended to firmly engage the top and bottom thereof; the sections being held in place by screws 65.

In the adaptation of my invention to any particular tank, the relation between gears 21, 2t, and a is so developed that one complete revolution of the latter represents the entire tank content. In Fig. 1, tube 3'! is shown in its extreme left hand position, i. e., representing an empty tank with the rack iii in its vertical (neutral) position (Fig. 2), it being assumed the tank float 63 has previously been lowered from the top of the tank to the bottom under gravity fall. As the tank fills, the float rises and cord 68 winds on drum 3! through the release of tension in spring (previously compressed by the downward movement of the float), as transmitted through the gear train 553, G7, 26 and 2'5 and cam 5i, cam lever 89 and rack 56. In this operation the tube 3? moves clock-wise and the main gear and cam 5! rotate in a similar direction. In one such complete revolution of the cam, the

i6 oscillates first to the extreme left position, then clock-wise to its furthest right position and fins. returns to its vertical (neutral) position; the reverse order occurring when the de. ends, te latter being of sufficient weight to operate the cam train and place the spring 58 in tension. in other words, the duty of rack 18 is to translate, in conjunction with cam 5|, cam lever 49 and the above-mentioned gears, the additive or subtractive effect (as the case may be) of the reeling operation of drum 3! incident to any change in liquid level through a zone of varying volume per unit depth, into the same fractional rotation of shaft ll as said change in level bears to the possible maximum; one complete revolution of said shaft and a similar reverse movement occurring during the respective filling and emptying of the tank.

The extension of shaft ll beyond cam 5| actuates the indicating and/or recording mechanism which may be of any well-known type and is herein conventionally illustrated by the gear box H attached to the rearof wall 3 and hands 12 and 13; the movement of the short hand corresponding to the tank capacity, the long hand for example making revolutions to one of the shorter and the face of wall it being suitably calibrated. With a tank of 1020 gallons capacity, for example, the wall face 3 (dial) may be conveniently graduated in thousandths, the short hand to rotate 1.02 times and the long hand 10.2 times for the complete movement (tank capacity) of shaft I'l; while in other cases the short hand 12 might be advantageously mounted directly on shaft H, or an extension thereof, and the long hand entirely omitted or caused to rotate at a different ratio than in the above mentioned example.

The floating spring 69, internally disposed in the drum 3i serves to take up any small play, such as incidental wave motion, while the guide 10 serves to retain the float cord in the helical groove 32.

In starting to fill, for example, a horizontally disposed tank of circular cross-section the volume of liquid increases at a lower rate than the change in liquid level, the cam lever 49, as actuated by cam 55!, tilting the rack l6 (carrying the gear 41) in such a direction that the gear 50 turns through a smaller angle than would be the case if the rack were stationary; the latter moving in the opposite direction to gear 50 and producing a deductible effect on the rotation of shaft l'l. Between points below and above the half full point, i. e., where the liquid volume alters more rapidly than the change in liquid level, the rack moves in the reverse direction to that first described, causing gear 50 to turn in the same direction as the rack and consequently through a wider angle; thus imparting an additive effect to the rotation of shaft H. The rack again reverses as the filling of the tank is completed. The corrective effects of the oscillat ing rack, as translated through the shaft l'l into equal angles of rotation thereof per equal volume change, are dependent on the shape of the cam 5! whose contour as depicted in Fig. 2 has been developed for the particular type of tank given as an example in this paragraph. Such cam may be employed without change for any similarly disposed circular tank, differences in diameter and length of tank being merely a question of gear ratios and indicating and/or recording dial adaptations.

A cam can of course be developed for tanks of any cross-section, the principle involved being the same; i. so designing the cam and gear that their movements are resolved into a final rotary motion over an are continuously proportional to the volumetric change involved. In practical applications such effect may be additive or subtractive in relation to the established movement of the main gear, depending on the cross-sectional form and the area thereof of the tank involved; but since most tanks follow conventional designs the greater portion of the apparatus involved in my invention may be duplicated for nearly all tanks with relatively slight changes in gear and dial calibrations, thus greatly reducing the cost of production.

The apparatus can be made small and compact and is adaptable for a dial in the vertical position (as shown) or in the horizontal plane, in which latter instance the float cord instead of emerging through the slot 42 would be passed through the hole SI in the stirrup 34. The indicating and/or recording mechanism may be so motivated by the shaft l! as to function at a remote point, and it is to be understood the casing illustrated in Fig. 5 may project through the tank, be replaced by other suitable type or dispensed with entirely. The invention is not limited in apparatus features to the precise arrangement and size relationship of parts as herein shown; for example, the spring for actuating the apparatus on the upward movement of the float may be applied to shaft 23. What I claim as new and desire to protect by Letters Patent 1. Apparatus for gauging the quantity of liquid in a tank comprising in combination a frame, a float, a rack oscillatively supported by said frame, a reeling drum mounted in said rack and engaged by a flexible means attached to said float, a rotatable shaft journalled in said frame, a gear train engaging said drum with said shaft, a means driven by said shaft adapted to oscillate said rack during the reeling of said flexible means through a path relational to the contour of said tank, and means for determining the degree of rotation of said shaft in terms of said quantity of liquid.

2. Apparatus for gauging the quantity of liquid in a tank comprising in combination a frame, a float, a rotatable shaft journalled in said frame, a rack oscillatively supported on said shaft, a reeling drum rotatably mounted in said rack and engaged by a flexible means attached to said float, a gear train engaging said drum with said shaft, a cam driven by said shaft adapted in a revolution thereof to oscillate said rack during the reeling of said flexible means through a path relational to the contour of said tank, and means for determining the degree of rotation of said shaft in terms of said quantity of liquid,

3. Apparatus for gauging the quantity of liquid in a tank comprising in combination a frame, a float, a rotatable shaft journalled in said frame, a rack oscillatively supported on said shaft, a reeling drum rotatably mounted in said rack and engaged by a cord attached to said float, a gear train engaging said drum with said shaft, a cam developed in a revolution thereof to the contour of said tank and driven by said shaft, a follower engaged by said cam adapted to oscillate said rack during the reeling of said cord through a path corresponding to said contour, guide means driven by said shaft for spacing said cord during said reeling, means for driving said shaft, and means for determining the degree of rotation of said shaft in terms of said quantity of liquid.

4. Apparatus for gauging the quantity of liquid in a tank comprising in combination a frame, a float, a rotatable shaft journalled in said frame, a rack oscillatively supported by said shaft, a reeling drum rotatably mounted in said rack and helically engaged by a cord attached to said float,

a gear train engaging said drum with said shaft, a positive cam developed in a revolution thereof to the contour of said tank and driven by said shaft, a follower engaged by said cam adapted to oscillate said rack during the reeling of said cord through a path corresponding to said contour, guide means driven by said shaft for spacing said cord during said reeling, spring means for driving said shaft on the upward movement of said float, and indicating means for determining the degree of rotation of said shaft in terms of said quantity of liquid.

5. Apparatus for gauging the quantity of liquid in a tank comprising in combination a frame, a float, a rotatable shaft journalled in said frame, a rack oscillatively supported on said shaft, a reeling drum rotatably mounted in said rack and helically engaged by a cord attached to said float, a gear train including an intermediate gear with integral pinion shaft mounted in said rack respectively engaging a pinion rigid with said drum and a main gear integral with said shaft, a positive cam rigid on said shaft developed in a revolution thereof to the contour of said tank, a follower engaged by said cam adapted to oscillate said rack in an arc corresponding to said contour, reciprocating guide means driven by said shaft for spacing said cord during said reeling, coiled spring means for driving said shaft during the upward movement of said float, and indicating means for determining the degree of rotation of said shaft.

FRANCIS M. HESS. 

